Inorganic persalts giving hydrogen peroxide in solution, such as sodium perborate, are widely used as a bleaching agent in detergent compositions. These persalts provide a satisfactory bleach when the detergent composition is used at high temperatures, e.g. 80.degree.-100.degree. C., but their action is rather slow to substantially nil at lower wash-temperatures.
It is known that organic peracids, e.g. peracetic acid, are active at lower temperatures and the use of peracids in detergent compositions, either as such or formed in situ, has been suggested to give the detergent composition satisfactory bleaching properties at lower wash-temperatures, e.g. in the 60.degree. C. wash-cycle.
A considerable saving of energy would be obtained if washing habits could be further shifted towards cold and cool water washing, e.g. below 40.degree. C., also for whites.
Unfortunately, however, organic peracids do not exhibit adequate bleaching at these low temperatures.
It is an object of the present invention to provide an improved bleach system which is also effective at temperatures below 40.degree. C.
Another object of the present invention is to provide a bleach composition suitable for use in cold and cool water washing at temperatures below 40.degree. C.
British Patent Specification No. 1,368,400 describes the activation of organic peracids by means of rather complex aldehyde or ketone compounds as the bleach activator. The use of a chloride salt (in fabric bleaching) and of a chloride or bromide salt (in hard surface bleaching) is described only in conjunction with said activated peracid system.